斐波那契数列的通项公式为an=√5/5[(1+√5)/2]^n-√5/5[(1-√5)/2]^n,设bn=√5/5[(1+√5)/2]^n,cn=√5/5[(1-√5)/2]^n则an=bn-cn,{bn}是公比为(1+√5)/2的等比数列,{cn}是公比为(1-√5)/2的等比数列,bn的前n项和Bn=...